1. Field of the Disclosure
The present disclosure relates to a liquid crystal display device and a method of fabricating the same, and more particularly, to a liquid crystal display device with a color filter on TFT (COT) structure in which a color filter is formed on an array substrate along with a thin-film transistor and a method of fabricating the same.
2. Description of the Related Art
In general, a liquid crystal display device is a display device in which data signals according to pixel information are individually supplied to pixels arranged in a matrix form to adjust the optical transmittance of the pixels, thereby displaying a desired image.
Accordingly, a liquid crystal display device may include a liquid crystal panel in which pixels are arranged in a matrix form and a drive unit configured to drive the pixels.
The liquid crystal panel may include a thin-film transistor array substrate and a color filter substrate attached to each other to maintain a uniform cell gap while facing each other, and a liquid crystal layer formed within a cell gap between the array substrate and color filter substrate.
Here, a common electrode and a pixel electrode are formed on a liquid crystal panel in which the array substrate and color filter substrate are attached to each other to apply an electric field to the liquid crystal layer.
Accordingly, when the voltage of a data signal applied to the pixel electrode is controlled in a state that a voltage is applied to the common electrode, liquid crystals in the liquid crystal layer are rotated by dielectric anisotropy according to an electric field between the common electrode and pixel electrode to allow light to be transmitted or blocked for each pixel, thereby displaying text or images.
FIG. 1 is a view schematically illustrating the cross-sectional structure of a typical liquid crystal display device, wherein part of the cross-sectional structure of a data line region is shown as an example for the sake of convenience of explanation.
Referring to FIG. 1, a typical liquid crystal display device may be configured with a liquid crystal layer (not shown) formed between two sheets of glass substrates 5, 10 while maintaining a cell gap through a column spacer 40 with respect to the glass substrates.
A gate line (not shown) and a data line 17 arranged in vertical and horizontal directions to define a pixel area are formed on the lower glass substrate 10, and a thin-film transistor, which is a switching element, is formed at a crossed region between the gate line and data line 17.
Here, though not shown in the drawing, a plurality of pixel electrodes and common electrodes are alternately formed within the pixel area.
Furthermore, the thin-film transistor may include a gate electrode connected to the gate line, a source electrode connected to the data line 17 and a drain electrode connected to the pixel electrode. In addition, the thin-film transistor may include a plurality of insulating layers 15a, 15b, 15c for insulation between the constituent elements and an active pattern configured to form a conductive channel between the source electrode and drain electrode by a gate voltage supplied to the gate electrode.
A color filter array is formed on the upper glass substrate 5, and the color filter array includes a black matrix 6, a color filter 7 and an overcoat layer 9.